Patent GB-793354-A (GB)
Title: Improvements in or relating to organometallic compounds
IPC: C07F17/00
Filed: 1955-07-12
Abstract: The invention comprises compounds of the formula RnMR1(4-n), where M is a metal of Group IVa of the Periodic Table, R is a radical containing a five-membered carbon ring with two conjugated double bonds attached to M through a carbon atom of the five-membered ring, being an unsubstituted or substituted cyclo-pentadienyl radical when n is 1 and R1 is alkoxy, cycloalkoxy, aryloxy and/or halogen or wnen n is 2 and R1 is alkoxy, cycloalkoxy or aryloxy, and being a multi-ring radical containing a five-membered carbon rign when n is 1 and R1 is alkoxy, cycloalkoxy, aryloxy and/or halogen or when n is 2 and R1 is alkoxy, cycloalkoxy or aryloxy.  The compound may also be of the formula <FORM:0793354/IV (b)/1> where M and R are as above, R1 is another R group, an alkoxy, cycloalkoxy, aryloxy group or a halogen atom, y is an integer and X is another R1 group or another <FORM:0793354/IV (b)/2> chain.  The compounds may be prepared by reacting an alkoxy, cycloalkoxy, aryloxy or halide compound of a Group IVa metal with an organo-magnesium Grignard reagent, an organoalkali metal, organo-cadmium or organo-zinc compound, the organo radical containing a fivemembered carbon ring with two conjugated double bonds, and isolating the reactants from moisture during the reaction.  The preferred reagents are the lithium and Grignard compounds.  Inert solvents such as ether may be employed. The monomeric compounds (RnMR1(4-n) may be partially hydrolysed by small amounts of water to give condensation polymers of formulae as above containing M-O-M groups.  In an examples an ethertoluene solution of cyclopentadienyl magnesium bromide is added under a nitrogen atmosphere to an ether solution of butyl titanate.  After refluxing, solvent is distilled off and the product diluted with benzene.  Titanium tetrachloride is added, precipitated magnesium salts separated and the solution vacuum distilled to give cyclopentadienyl dibutoxy titanium bromide. Other examples describe the preparation of biscyclopentadienyl titanium dibromide, indenyl dibutoxy titanium monobromide, cyclopentadienyl zirconium trichloride, and cyclopentadienyl titanium trichloride.ALSO:Compounds of the formula RnMR14-n, where M is a metal of Group IVa of the Periodic Table, R is a radical containing a five-membered carbon ring with two conjugated double bonds attached to M through a carbon atom of the five-membered ring, being an unsubstituted or substituted cyclopentadienyl radical when n is 1 and R1 is alkoxy, cycloalkoxy, aryloxy and/or halogen or when n is 2 and R1 is alkoxy, cycloalkoxy or aryloxy, and being a multi-ring radical containing a five-membered carbon ring when n is 1 and R1 is alkoxy, cycloalkoxy, aryloxy and/or halogen or when n is 2 and R1 is alkoxy, cycloalkoxy or aryloxy, may be condensed by small amounts of water to give condensates of the formula <FORM:0793354/IV (a)/1> where M and R are as above, R1 is another R group, an alkoxy, cycloalkoxy, aryloxy group or a halogen arom, y is an integer and X is another R1 group or another <FORM:0793354/IV (a)/2> chain.  The monomeric compounds [RnMR14-n] may be used as catalysts for the polymerization or vulcanization of butadiene, styrene, acrylates and methacrylates and as modifiers for film-forming compositions.  In an example, cyclopentadienyl dibutoxy titanium bromide in ethertoluene solution is hydrolysed by dilute sulphuric acid to give solid condensate.  The same product is obtained on exposure of the cyclopentadienyl dibutoxy titanium bromide to air.  A further example describes a composition comprising cyclopentadienyl dibutoxy titanium bromide dissolved in a solution of ethyl cellulose in benzene-butanol; this composition yields a hard tack-free film.